The Northland Regional Council is keen to hear from eyewitnesses of historic floods in the region.
The council has embarked on a major project to reduce the flood risk in 27 catchments across the north.
A councillor, Bill Rossiter, says much of the information on how rivers will behave when flooded now comes from computer modelling, but the council still needs information from people.
Mr Rossiter says those who have been attending community meetings on flood protection have come up with some very useful details of floods, such as the one that swamped Whangarei in 1956.
He says the regional council would also welcome old family photographs of major floods in the north.